Extract JetWhileExpressionBase.

Adapted from https://github.com/develar/kotlin/commit/9ac92f00a163ddf9bb3a6d7a6f4f47578c8c6dfb by develar.

compiler/frontend/src/org/jetbrains/jet/lang/psi/JetDoWhileExpression.java

@@ -18,13 +18,11 @@ package org.jetbrains.jet.lang.psi;
 
 import com.intellij.lang.ASTNode;
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-import org.jetbrains.jet.JetNodeTypes;
 
 /**
  * @author max
  */
-public class JetDoWhileExpression extends JetLoopExpression {
+public class JetDoWhileExpression extends JetWhileExpressionBase {
     public JetDoWhileExpression(@NotNull ASTNode node) {
         super(node);
     }
@@ -38,10 +36,4 @@ public class JetDoWhileExpression extends JetLoopExpression {
     public <R, D> R accept(@NotNull JetVisitor<R, D> visitor, D data) {
         return visitor.visitDoWhileExpression(this, data);
     }
-
-    @Nullable @IfNotParsed
-    public JetExpression getCondition() {
-        return findExpressionUnder(JetNodeTypes.CONDITION);
-    }
-
 }

compiler/frontend/src/org/jetbrains/jet/lang/psi/JetWhileExpression.java

@@ -18,13 +18,11 @@ package org.jetbrains.jet.lang.psi;
 
 import com.intellij.lang.ASTNode;
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-import org.jetbrains.jet.JetNodeTypes;
 
 /**
  * @author max
  */
-public class JetWhileExpression extends JetLoopExpression {
+public class JetWhileExpression extends JetWhileExpressionBase {
     public JetWhileExpression(@NotNull ASTNode node) {
         super(node);
     }
@@ -38,9 +36,4 @@ public class JetWhileExpression extends JetLoopExpression {
     public <R, D> R accept(@NotNull JetVisitor<R, D> visitor, D data) {
         return visitor.visitWhileExpression(this, data);
     }
-
-    @Nullable @IfNotParsed
-    public JetExpression getCondition() {
-        return findExpressionUnder(JetNodeTypes.CONDITION);
-    }
 }

compiler/frontend/src/org/jetbrains/jet/lang/psi/JetWhileExpressionBase.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2010-2012 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.jet.lang.psi;
+
+import com.intellij.lang.ASTNode;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import org.jetbrains.jet.JetNodeTypes;
+
+/**
+ * @author Pavel Talanov
+ */
+public abstract class JetWhileExpressionBase extends JetLoopExpression {
+    public JetWhileExpressionBase(@NotNull ASTNode node) {
+        super(node);
+    }
+
+    @Nullable
+    @IfNotParsed
+    public JetExpression getCondition() {
+        return findExpressionUnder(JetNodeTypes.CONDITION);
+    }
+}